Electropneumatic brake valve



Feb. l2, 1929.

C. A. CAMPBELL ELECTROPNEUMATIC BRAKE VALVE Filed Oct. '7, 1927 3Sheets-Sheet 2 attozmqn Feb l2, 1929.

ELECTROPNEUNATI C BRAKE VALVE Filed oct. v, 1927 :s sheets-sheer 3anonwq Patented Feb. 12, 1929.

UNITED STATES PATENT OFFICE.

CHARLES A. CAMPBELL, OF WATERTOWN, NEW YORK, ASSIGNOR TO THE NEW You AIRBRAKE COMPANY, A CORPORATION 0F NEW JERSEY.

ELECTROPNEUMATIC BRAKE VALVE.

Appncauon ined october 7, 1927. seriai No. 224,718.

This invention relates to railway brakes, and particularly to theso-called electropneumatic type novv used in high speed tractionservice, but not necessarily confined to that field of use alone.

Gene ally stated, t-he ordinary component elements oit' such a systemare a brake cylinder, auxiliary reservoir and triple valve, conformingin a general Way to known practice in automatic air brakes, and anurnber ot electrically actuated valves, usually three, which exert a`modifying eiiect on the functions of the triple valve and which arecontrolled by a switch operated synchroously with the engineers brakevalve to control the electric valve circuits simultaneously throughoutthe train.

One electric valve, commonly known as the emergency magnetvalve,operates to produce an emergency function of the triple valve. This isdone as a rule by venting the brake pipe air to atmosphere. Theemergency magnet valve is rendered active when the engineers brake valveis in emergency position.

The second electric valve is known as the service magnet valve andfunctions to produce a moderate reduction of brake pipe pressureWhenrthe engineers brake valve is moved to service position. It Ina-yaccomplish this result in a variety of Ways, butV venting of t-he brakepipe air at a restricted rate to the brake cylinder is preferred.

The release magnet valve is the third of the group and is in effect aretaining valve operable to close the exhaust port from the triplevalve.

The purpose of the release valve to permit graduated release and topermit recharge of the auxiliary reservoirs While the brakes 1re heldapplied. To accomplish this the valve is given a position known asholding position 7 in which the valve functions as .in release but inwhich. unlike release the release magnet valve is actuated. It thusbecomes possible to recharge the auxiliary reservoirs Without releasingthe brakes by moving the engineers brake valve to holding position. andto produce a graduated release oit the brakes by shifting the engineersbrake valve .alternately between running and holding positions.

lith brakes of this character high brake cylinder pressures areoftenrequired particularly in emergency, and it only one auxiliaryreservoir used, it is obvious that large reservoirs and relatively highbrake pi e pressures must be used. The brake cylin er pressure inemergency can be made hivfher by using a supplemental reservoir Whic isdrawn upon in emergency,'or by using main reservoir pressure inemergency, or by using a combination of the two. Where the supplementalreservoir is used the release of the brakes is sluggish, and Where mainreser-` voir pressure is used it is diicultto release the brakes at all,because brake cylinder and auxiliary reservoir pressure Ina` be raisedto a point at which they excee the normal" brake pipe pressure with theresult that the triple valve can not move to release position.

` Une important purpose of the present invention,.tiereforeis to producea device of this character in which supplemental reservoir pressure ormainreservoir pressure, or

both, may be used in emergency braking,

and in which rapid release following emer- `gency Will be secured. Thisresult is attained'by certain details of construction of theelectro-pneumatic valve mechanism and its relation to the triple valvemechanism.

Generally stated, the release magnet valve operates to admit air to andexhaust it from a pncumatically operated valve which performs theretaining function. The air for y operatingr the pneulnatically operatedvalve is takenifroln the slide valve chamber of the triple valve whichis partially isolated from the auxiliary reservoir by means of a` choke.This accelerates release.V Furthermore, when the release magnet valvevents the pneumatically actuated retaining "alve, it also vents theslide valve chamber unless and until this valve is in release position.

Another important feature of the present invention .is the combinationwith an electropneumatic valve includingr what is essentially a plaintriple valve of an emergency vent valve mechanism so contrived that inaddi tion to its ordinary functions it Will produce an emergencyapplication if brake pipe pressure is reduced at an extremely low rate,such a loiv rate reduction, for example, as occurs when a ln'ake pipe isfrozen and leakage trom the system gradually depletes the pressure. Thisemergency` valve is y claimed broadly in my applicationuserialv l` No.208,629 filed July 26, 1927, and hence is claimed in the presentapplication only in a special relation. Normally the valve functions toAproduce an emergency application by purely pneumatic means. In thepresent device itl is so combined with an electropneumatic brake valvethat by pneumatic means it admits main reservoir air to the brakecylinder and serves as the sole means for performing' this function inthe general combination claimed. Further, it operates through electricalmeans to cause all the emergency magnet valves throughout the train tofunction and cause simultaneous emergency application on all cars of thetrain. This last feature is of particular importance because the slowemergency function is likely to be local to a single car and if theemergency function Were coniined to that car, as it would be in the caseof frozen hose7 a breakin-two is likely to occur. rIhe electricconnections, by insuring simultaneous emergency throughout the train7will eliminate this risk.

Fig'. 1 is a piping; and wiring diagram of the complete system for atwocar train, (motor car and trailer). Y

Fig. 2 is a vertical axial section of the pipe bracket, the triple valveand the pneuw matically actuated emergency switch.

Fig. 3 is a vertical axial section ofthe electro-pneumatic valvemechanism and of the emergency valve mechanism.

Fig. 4 is a fragmentary view of the triple slide valve with itsgraduating' valve and seat, showing' the parts in service position.

Fig. 5 is a similar view showingthe parts in service lap position.

Fig. 6 is a similar view showing the parts in emergency position.

Fig. 7 is an enlarged view of a portion of Fig. 3.

In Fia'. l the engineers brake valves are omitted altogether, and theswitching mechanisms which are operated in synchronism Y withcorresponding brake valves, as is common practice, are shown only indiagram.

In F igs. 2 to (i inclusivev9 a familar dia- Iqgrammatic met lod ofshowing the ports has been adopted by which all the ports are shown inthe plane of section to permit their simultaneous functions to betraced, but it will be understood that a more compact arrangement ispossible by a somewhat different location of the ports, as will bereadily understood by hose skilled in the art.

Figs. 2 and 3 together form a complete vertical section of the improvedelectropneumatic valve mechanism.

In order to simplify the tracing' of the ports, fragmentary portions ofthe electroaneumatic mechanism and of the emerp'enc l s Y valvemechanism have been shown in position as portions of Fig. l, and thefragmentary portion of the pipe bracket has been included as a portionof Fig. 2.

The complete valve is made up of six units, which are designated on. thedrawing,r by letters. The entire device is supported by a pipe bracket Ato which all pipe con nections are made and against ported faces ofwhich four of the other units arc bolted in sealing' relation. Thetriple valve unit is shown at Il; the emergency valve unit is shown atC; the pncuniatically actuated emergency switch is shown at I): the mainreservoir bypass valve is shown at Fi; and the electro-pneumatic valveunit is shown at F.

Pipe bracket.

The pipe bracket'rr is formed with an attaching flange ll and isprovided with a plurality of through passages, which uf'ill be describedafter the triple valve mechani have been explained. There is face with agasket, indicated by the numeral l2. by means of which the triple valveunit li is sea-led to the bracket; ported 'tace with ported gasket,indicated generally by the numeral 13, by means of which the emergencyunit C is sealed to the bracket A.; a ported face and ported gasket 'laby means of which the electro-pileumatic valve unit F is sealed 'to 'thebracket, and the ported face with ported gasket. indi :ated generally bythe numeral l5. by means of which the pneumatically actuated emergencyswitch D is sealed to the pipe bracket. There is an exhaust connectionlf3. shown threaded. to permit the attachment of an cxhaust pipe ifdesired; a threaded main reservoir connection 17; a threaded brake pipeconnection 18; a threaded auxiliary reservoir connection 19; a threadedsupplemental reservoir connection. 2l; and a threaded brake cylinderconnection Tripe cette@ Wait.

Thetriple valve unit B consists of a body 23 provided with the usualvalve bushingT 24 enclosingl the usual slide valve chamber 25 and acylinder bushing' 26 forming' the cylinder in .vhich the triple piston27 works. T here is also the usual front cap 289 a 2raduatinpr thimble29. and a giradustingl spring; 3l. The piston 2T has the usual rod whichis formed with lugs 33 and 3st arranged to collide with and move thetriple slide valve 35 but to permit some lost motion of the pistonrelatively to the valve. Mounted on the triple slide valve 35 is agraduating` valve 3o which is confined in a notch in the rod 32 so thatit has no lost motion relatively thereto. rIhe end of `the rod 32 coactswith a re stop 3T urged to the left by a retard spnng' 38, the partsbeing` so arranged that the retard stop 3'? llG arrests the piston 27 innormal charging position, but itt the spring 38 be overpowered, willpermit the piston to move to the right a slight distance to a quickcharging position.

Formed in the lower portion ot the body 23 is a quick service chamber 39which in release position is at atmospheric pressure and into whichbrake pipe air is vented as the valve starts toward service position toaccelerate the servit-e movement of the piston 2T. Mounted on the body23 a safety valve or relief valve ll ot lrnown construction, whosefunction to vent excessive brake cylinder pressure in serviceapplications. The bushing 2l is 'formed with a ported seat for the valveas is usual, and the ports in said seat are as follows: a supplementalreservoir charging port 42, an auxiliary reservoir charging port ld, areleasing vent port 4l, quick service port lo, exhaustr port 46, brakecylinder port 47, satety valve port 4S, brake cylinder port 49 andsupplemental reservoir equalizing port The supplemental reservoircharging port Ll2 coact-s with the through Vport .52 in the slide valveand is open only in normal release and recharge position, which` is theposition shown in Fig. 2. Charging ot the supplemental reservoirthere't'ere occurs only when the releasing pressure wave in the brakepipe is not abnormally high. The auxiliary reservoir charging port d3 iscontrolled by the slide valve and registers with a through port 53 inboth the release and recharge positions of the valve, namely, that shownin Fig. 2 and that which occurs when the piston 27 overpowers retardstop spring 38. lVhen the retard stop spring 38 so overpowered thepiston. moves beyond a teed port in bushing 26 and an additionalcharging passage opened by way ol choke 55 and passage 5G to slide ialvechamber In starting to service the graduating valve 56 first movesrelatively to the v'alve 35 which is then at rest, and functions tirsttoblank the port and then to connect the port 53, by means ot' recess 5T,with port 58 which extends through lthe slide valve and then in registerwith the quick ce port- The port 58 and recess 5T, in addition to thefunctions just described, serve in the release and recharge positions toconnect port l5 with port 50 in the slide valve l5 and hence with theexhaust recess tl and exhaust port 16. The release vent port @tl isblanked hy the slide valve 35 in both release and recharge positions butis connected by port 62 in the slide valve "y oo with the valve chamberQ5 in service, service lap and emergency positions. This release ventport the passage through which air is vented.` under the control ot theelectropneumatic mechanism, from the valve chamber 25 to accelerate thereleasing movement oi the piston Recess 6l serves to connect the brakecylinder port i7 and the exhaust port -flt in both release and rechargepositions. The brake cylinder port i7 also coacts with the through portin the slide valve 35 which registers with it in service, service lapand emergency positions.

ln service and emergency positions auxiliary reservoir air flows fromthe valve chamber 25 to the brake cylinder through theseregisteringports, but in service lap position the port ti() is blankedby the graduating valve 36. The safety valve port 48 and the brakecylinder port #19 are connected with each other by a recess 63 in theslide valve 35 in service, and service lap positions only. At all othertimes they are blanked. The supplemental reservoir equalizingport 5lhlanked by the slide valve 35 in all positions except emergency. Inemergency it is cleared by the slide valve to permit supplementalreservoir air to flow to the valve chamber 25.

Between the bralte pipe connection 18 and the space within the front cap28 to the left of the piston 27 there extends a brake pipe passage t-lwhich has branches, one extending to the Vcharging port 43, anotherextending into the emergency valve mechanisml C, hereinafter described,and a third exteiuling.;r into the electro-pneumatic mechanism Fhereinafter' described. Extending from the suplemental reservoirconnection Q1 is a supplemental reservoir passage 65 which has onebranch extending tothe charging port l2, and a ln'anchextending past thecheck valve G6 to t-he equalizing port 51. This second branch passage ismade up in part of grooves 67 and 68 which are formed within the body Q3and extend around the bushinfr 24, as is indicated on Fig. 2. Theauxiliary reservoir connection 19 connnunicates through a choke 69 witha passage 71 which loads to the triplo valve chamber' Q5. The capacity'ot' the choke `69 is such as to restrict flow to and from the auxiliaryreservoir 'torthe purpose ot allowing` a uniform rate ofbrake'applications on mixed sizes of equipments. There are branchesVirom the passage 71 which lead both to the electro-magnetic valve unitF and to the emergency valve unitfC, as will be hereafter described. Thebrake cylinder connection connnunicates` with a passage 72 whichconnects with the brake cylinder ports 47 and 49 and whiclralso has abranch leading to the electrowpneunlatic valve unit F. The mainreservoir connection 17 leads to a passage T3 which extends into theelectropneumatic valve imi-tion F. The release vent port All in theslide valve seat communicates with ,the (passage .74 which leads to theelmetro-putainiatic valve portion "F, as will be later described. Thequiekservice lll() lil) port l5 is connected by passage T5 with thequiclr service chamber 39. The exhaust port el@ is connected by passa-geTG with the interior of the electro-pneumatic valve unit. l?. l`his isthe passage which leads to the electro-pneuniatically actuated retainingvalve and by controlling it the retaining valve thus controls exhaustoit the triple valve. Safety valve port 48 is connecter to the satetyvalve Lll by passage 77 which is formed iu the body 523 and which isshown partly in dotted lines in Fig.

rlhe triple valve above described has many oi the characteristics ot aplain triple valve. lt is not strictly necessary to certain features otthe invention that a supplemental reservoir be used at alla or that thevalve be capable ot giving two charging' rates, or thatit be equippedwith the quick service chamber B9. The chai es to eliminate any or allof the features aoove mentioned will be obvious to those skilled in theart and need not be discussed.

lVith this device is used an emergency valve which, in its broadestaspects, is inerely a brake pipe vent yalvey but which in the particularcombination here involved possesses certain incidental features by meansof which the response oit any eniergency f'alve in a train causes,through electrical means, the functioning' of all emergency valves inthe train. Another incidental feature of the emergency Valye is thecontrol ol admission of main reservoir air to the brake cylinder inemergency.

Emergency calce.

he upper and supporting portion of the emergency valve unit G consistsot a casting 81 formed with a chamber 82 to which the brauch of thepassage 64; already mentioned leads. lnto this chamber there projects ahollow member formed as a unitary portion ot the casting, the hollowmember being provided with a vent port 83 which leads to and terminatesin an upwardly facing valve seat Sel. A vent valve 85 coa-cts with thisseat and is guided by a shouldered stem slidably mounted in a housing;8T. The housing 87 is screwed into the casting` 81 and serves to encloseand sustain a coil springh 88 which surrounds the stem 86, and seatsagainst the shoulder thereof, so as to urge the valve constantly towardthe seat Set. Just above the valve 85 the rod 86 is provided with alarge annular flange 89. 'lhe passage 83 leads to a yalye seat 01against which a check valve 02 seats. 'lhe check valve 92 is guided by asleeve 93 which slides in a cap Se threaded into a portion of thecasting 81. The cap 04e is vented at 95Y and houses` a coil spring; 06which serves to urge the valve 02 in a closing` direction. The strengthot the spring 9(3.i

. such that the valve will open under pressure oi approximately tenpounds per square inch. Air discharging` past the valve 92 llows toatmosphere through the passage 07.

Bolted to the lower tace ot the casting' S1 is a hollow casting 9S, atight joint being secured by ol an interreningv gasket. 'lhe castinp` 08is formed with a passage 09 which communicates with a branch ot theauxiliary reservoir passage 71 heretofore inentionech and communicationis through a choke plug 101 inserted in a recess adj acent the plane olseparation ot the castings S1 and 98.

Formed in the casting 98 is a reservoir 102 and between this reservoirand the projection in which the vent 83 is formed, there is mounted anannular cylinn der bushing 103 having at its lower end an annularupwardlj-,fv projecting sealing` rim 10s. Slidably mounted in thebushingl 103 is a pistou 105 haring a downwardly extendine' stein 106which is guided in a bushing` 10( in the upwardly extending boss 108.The space below the stem 106 is Vented at 109 to the interior oit thereservoir 102. Piston 105 `n'ovided with the usual piston and carries onits lower tace a gasket adapted to seal against the rim 101 when thepiston is in its lowermost iosition. The piston ring' and gasket areclearly shown in Figs. 2 and 3.(a but are not numbered, to avoidconfusion. The piston ringn prevent-s ordinary leakage and the gasketproduces an absolute seal in the lowermost position of the piston.

The stem 106 oit the piston is formed with an axial bore 111 leadingfrom the space above the piston and terminating` in an annular groove onthe outer lace of the stein. ln the lowermost position ot' the pistonthis groove is slightly below the upper end ot the bushing,` 107 and theclearance between the stem and the bushing, which is so1ne what enlargedin Fig. '7 to make it visible, is su'flicient to permit chargingot thereser- Voir 102 by way ot the port 111 at the proper rate. This rateshould be restricted to avoid any tendency to oyercharge the reservoir.Should the clearance increase by wear, the resulting' overcharge wouldhave a tendency to cause undesired emergency applications, and lor this'cason an outward opening` lightly loaded checl; valve 112 provided tovent any ovcrcharge by way of the passage 99 and eholie 101 to theauxiliary reservoir by way of passage 7l.

In service position upward motion of the piston 105 is arrested by pins113 Vfixed thereto, which in such position engage the flange 89 on stem8G. lt brake pipe pressure is beingI reduced at a service rate1 i. e.,relatively slowly, the resistance ot the spring 88 will be sutlicient toarrest piston 105 while the valve 85 remains closed. At this Cil lil)

time Jthe terminal groove of port 111 clears the upper end ot bushing107. The port is so dimensioned that it will allow pressure fluid fromthe reservoir 102 to flow back to the brake pipe at the service rate. Itis inadequate, however, to keep pace with an emergency reduction, andaccordingly upon emergency reduction the piston 105 overpowers spring88, opens va lve 85, and allows brake Ipipe air to flow by way ofpassage 83 and check valve 92 to the atmosphere. The space between valveseat 84 and check valve 02 is connected by a passage 114 with thepneumatic emergency switch D and with the actuating motor of the mainreservoir ily-pass valve E.

It should. be remembered that the check valve 02 retains about tenpounds back pressure in the passage 83, and this pressure de liveredthrough the passage 114 is caused to pcrt'orni certain emergencyfunctions, hereinafter described. This port 114 is the 'connection bywhich the emergency valve mech` anisin of my prior application, aboveiden titled, is caused to perform certain special functions inconjunction with electro-pneu matic brake valves.

The mechanism so tar described will function to produce emergencyapplications in the usual way, but it desired to insure emergency appliAation in the event of a slow depletion of brake pipe pressure. Toeffect this result there formed in the cast-ing 98 a second reservoir115. The passage 116 leads from the reservoir 102 through a valve seatbushing 117 to the interior of the reservoir 115. A check valve 118coacts with seat 11T and opens toward the reservoir 115 against theopposition of a light spring 119. lhe purpose in using a light spring isto insure that the reservoir 115 will be charged nearly to the pressureoli' reservoir 102. Fixed to the valve 118 is a stem 121 which hasguiding wings or vanes where it passes through the bushing 117 and whichmakes a close sliding fit with the bushing 122 so as virtually topreclude leakage at this point. The stem 121 extends through chamber 123to w rich leads a branch of the brake pipe passage 64. The pasage 116 iswholly out oiE communication with the brake pipe pas 64. The upper sideot the chamber 123 formed by the lower annular end oi" a cylindricalbushing 124, such lower end being formed with an upwardly extendingannular sealing rim Mounted in the bushing 124 is a cup-shaped valve126, open at .its upper end. At its lower end this valve is in thrustrelation with the stem 121 and carries an annular gasket which in thelower position of the valve, seals with the rim 125. The upper end ofthe valve 126 is slightly reduced cr shouldered so as to have a relatively reduced sealing area fith the gasket 12T when the valve is in itsuppermost position. The gasket 127 is sealed in place by a threaded plug128 having an axial vent port which connects the `interior of the valve126 to atmosphere, as clearly shown in Fig. 3.

A spring 129 urges the piston downward, the strength of the spring beinsuchthat it will be overpowered by a mo erate brake pipe pressure, saytwenty pounds per square inch. A passage 131 `connects with the interiorofthe bushing 124 at its opposite ends.

Starting with a completely discharged brake system, the valve 126 willbc in its lowermost posit-ion with its gasket sealing on shoulder 125,but when a brake pipe pressure of approximately twenty pounds ias beenreached, valve 126 will move up and its reduced end will seal on gasket127. Such motion of valve 126 allows valve 118 to close, but it isopened by a slight preponderance of pressure in chamber 122 and chargingcontinues. Thereafter as long as brake pipe pressure is above twentypounds, valve 126 remains in its uppermost position and valve 118 willremain closed no matter how depleted the pressure in chamber 102 maybe.. But if brake pipe pressure falls below say twenty pounds, as itmight do without applying the brakes in the event of a frozen hose or anaccidentally closed angle cock, the valve 126 will move suddenlydownward, unseat the valve 118 and allow pressure from reservoir 115 toflow into reservoir 102. The sudden access of pressure to the spacebelow piston -125 will produce an immediate emergency application, andthis emergency application, like all other emergency applications whichoccur in this mechanism, will operate through the passage 114 upon thepneumatically operated switch. The passage 131 acts to equalize thepressures above and below the valve 126 as soon as this starts itsdownward motion and thus serves to accelerate the downward motion of thevalve once it has commenced.

Pnemnatz'cally operated switch.

The switch unit D is enclosed by a cast body 135 into which is threadeda cupshaped cylinder 136 closed at its top by a threaded plug 137. Thepassage 114 is continued in body 135 and cylinder 136 and leads to theupper end of the cylinder space. The lower end of the cylinderis formedwith .a guide 138 for the hollow stem 139 of a.

i hub 147 downward relatively to the rod and piston and a stop 151 fixedon rod 146 limits such motion. Fixed on the removable cover ot chamber144 are two contacts 152 insulated from the cover and hence from eachother.

Then the emergency valve C functions to produce an emergency applicationpressure retained by valve 92 llows through passage 114 to the spaceabove piston 141, forces this piston downward and causes contacter 148to bridge contacts 152, 152. rllhese are so connected as to actuate allthe electrod pneumatic emergency valves in tire train, as will bedescribed.

The pressure above piston 141 is bled away after the emergencyapplication has been effected, the bleed port being associated. with arelated mechanism, namely the main reservoir by-pass valve E.

Main reservoir (y-poss ocloe.

is a piston 158 having` a bleed poi-t 159. 'lhe cylinder space abovepiston 158 is vv ved to atmosphere at 161.

The piston 158 has a stem 162 which r altes a close sliding lit in abushing 163 which closes the uppei` end et the cylinder. Stem 162 iscounterbored at its end to receive the pilot 164 ot toe by-pass valve165. This valve is normally held on its seat 166 by CTL spring 167 andby main reservoir pressure arriving through passage 73. Spring 167 isenclosed in a tubular guide 166 which receives an upward extension ofvalve 165. From this chamber a passage 169 leads a reversely seatedcheck valve 171 urged closed by spring 172 which will open underpreponderating pressurein passage 169 to at.- mit air to a branch ofbrake cylinder passage 72. A safety valve 17 3 of usual toi-m (similarto safety valve 41) vents excess brake cylinder pressure in emergency.Valve 173 is set to retain a higher pressure than valve 41 which isoperative in service but not in emergency applications {see Figs. 4 and6).

l/lvlhen the emergency valve C functions pressureretained by loadedvalve 92 pene trates. by way of passage 1147 to the space below piston158, forcing this piston up and unseating valve 165. Thereupon mainreservoir air trom connection 17 flows by passage 73 past valve 165 andthrough passage 169 to valve 171 which it unseats. The flow continuesvia passage 72 to the bralfle cylinder connection 22. Excess pressure isvented by safety valve 173. Bleed port 159 is dimensioned to ventpassage 114 and allow ,isa

valve to close after a proper interval. Such ventingV also allows spring142 to restore piston 1417 disconnecting contacts 152. The restoringmovements of pistons 141 and 158 depend on the relations of piston areato restoring-spring strength, and such movements are not necessarilysimultaneous.

Eleci'opuemnato mechanism.

The three units which make up the electropneumatic mechanism consistcach of a pneun'iatically actuated valve and an electrically actuatedcombined admission and exhaust valve for controlling the pneumaticactuation of said pneumatically actuated valves. ln the rase ot' therelease valve the exhausting action ont the electrically actuated valvealso vents the triple valve chamber to initiate or assist in initiatingshitting of the triple valve piston 27 to release position.

lhe pneumatically actuated valve element ot the electro-pneuniaticemergency unit is located in a chamber 175 to which brake pipe passage64 leads7 and consists of a cup-shaped combined piston and valve 17 6mounted in a cylinder bushing 177 and urged into sealing engagement withannular seat 178 by spring 179. The bushing 177 is ported a 181 so thatvalve 176 controls l'low trom brale pipe passage 64 to atmosphere byvvay of passage 162 and so that when it is closed it is subject to brakepipe pressure over a part ot its area. vWhen the valve opens the entirearea exposed. Valve 176 is controlled by an electrically actuated valveinechani. in chamber 184 which has a ported inlet valve seat 185 andopposed thereto a ported exhaust valve seat 166. il branch o1 brake pipepassage 64 leads to `the portin inlet seat 165 and exhaust scat 186 isconnected to atmosphere by passage o lnlet valve 168 is normally heldtrom its by spring 189 and is counterbored to receive a stem on exhaustvalve 191 which serves to hold the two valves alined and in tnrustrelation with each oth r.

Exhaust valve 191 is connected to the armature oit the valve actuatingmagnet indicated generally by the numeral 192. 'the winding ot themagnet 192 is normally deenergized so that spring'169 holds the er;nhaust valve 191 closed and the inlet valve 166 opened. The excitationsof the winding 192 closes the inlet valve 166 and opens the ehaust valve191. Leading from the chamber 164 is a passage 193 which communicateswith the space above the combined piston and valve 176. lt follows thatunder normal conditions this valve is held closed by brake pipe pressureacting on its upper end assisted by the spring 179. ln emergency thewinding of the actuating magnet 192 is excited. lnletvalve 188 isclosed, the exhaust valve 191 is opened, the space above iii thecombined piston and valve 17 6 is vented to atmosphere, and brake pipepressure, acting through the port 181, forces the piston and valve 176upward permit-ting bra-ke pipe pressure to discharge directly toatinosphere through ported seat 178 and passage 182.

The service valve mechanism is essentially similar, except that it ventsbrake pipe air to the brake cylinder instead of venting it toatmosphere.

The pneumatically actuated valve element of the electro-pneumaticservice unit is mounted in a chamber 195 to which the brake pipe passage64 also leads, and consists of a cup-shaped combined piston and valve196 mounted in a cylinder bushing 197 and urged into sealing engagementwith an annular seat 198 by a spring 199. The bushing 197 is ported at201 so that valve 196 controls flow from the brake pipe passage 64 tothe brake cylinder passage 72 by Way oit choke 202, passage 203 andcheck valve 204. The check valve is provided to prevent back How fromthe brake cylinder' to the brake pipe. The choke 202 is inserted toreduce the rate of venting tloW in service to the desired amount. lVhenthe valve 196 opens its entire lower area is exposed to brake pipepressure, and it then nioves to its upward limit of motion and seatsagainst the gasket 205 which is provided to prevent the escape of brakepipe air to atmosphere. No such gasket is necessary on the piston andvalve unit 176 because when this opens direct venting to atmosphere isdesired.

rlhe valve 196 is controlled by an electrically actuated valve mechanismin a chamber 206. This chamber has a ported inlet valve seat 267 and anopposed ported exhaust valve seat 208. The branch of brake pipe passage64 leads through a choke 269, to the port in the inlet seat 207. Theport in exhaust seat 208 is connected to at.- mosphere by passage 211.The chamber 206 is connected to the space above the pis` ton valve 196by a port 210. Inlet valve 212 is urged from its seat by a spring 213and is counterbored to receive a stem on the exhaust valve 214, thepurpose of the stein being to hold the tvvo valves alined in thrustrelation with each other. The exhaust valve 21st is connected by a stem215 With the armature, not shown, of a magnet or solenoid winding 216,similar to the unit 192, and like that unit normally deenergzed. Fromthis itl follows that the exhaust valve 214 is normally closed, theinlet valve 212 normally opened and the combined piston and valve 196normally in its lower Aposition in Whichit seals against gasket 198 andprevents the flow of brake pipe air to the brake cylinder.

lVhen the engineer moves his brake valve to produce a serviceapplication, the winding 216 is energized while the brake valve remainsin service position. This closes valve 212, opens valve 214, venting thepressure above valve 196 and causing this to which is urged to its seatby a spring 224.

This check valve controls tiow to a chamber 225 which directly connectedby passage 226 with the exhaust connection 16. The valve closes in thedirection of exhaust How. and hence when allowed to close it is seatedby pressure ot the outflowing exhaust as Well as by the spring 224.Under norinal` conditions it is held open by a pilot 227 Which extendsthrough the bushing 222 and which engages the end of a piston 228slidably mounted in a bushing 229 and having a gasket which sealsagainst the annular sealing rim 231 on the upper end ot' the bushing229. The piston 228 1s not spring urged but is held up by fluid pressureadmittcd by the electric release valve from the auxiliary' reservoir.The reason for having the piston 228 seal against `the shoulder 231 isto preclude the leakage of auxiliary reservoir air to atmosphere by Wayof chamber 225 and passage 226. Chamber 232 below the piston 228 is incommunication with the valve chamber 233 and with the releasing vent ort44 by Way of passage 74 and its branc ies. The valve chamber 233 isprovided With a ported inlet valve seat 234, whose port is in directcommunication with the auxiliary reservoir passage 71 and with a portedexhaust valve seat 235, Whose port leads to atmosphere by way of passage`236. The inlet valve 237 which coacts with seat 231 is urged away fromits seat by a spring 238 and is counterbored to receive a projectingstem on the exhaust valve 239 which normally seats on the exhaust valveseat The exhaust valve 239 is unseated and the inlet valve 237 seated inopposition to the action of the spring 238 by an armature connected by astem 241, the armature being drawn downwardly by the excitation of thewindings of the release magnet 242. Under normal conditions the releasemagnet is deenergizcd, and auxiliary reservoir air flows through theseat 234 to the chamber 232 and forces piston 228 to its uppermostposition. This unseats the valve 223.

lVhen the engineer moves his brake valve to holding position, `theWixnlings ot' therella') lease magnet 242 are Xcited and its armaturesforced downward, closing the inlet valve 237 and opening the exhaustvalve 239. This vents pressure l? om chamber causing piston 229 to movedoivnivard and valve 223 toclose. The eli'ect ot this is to close theexhaust port of the triple valve.

It, as is ordinarily the case, the triple valve is in servie-e, servicelap or einer-gene*u position (see Figs, l, 5 and 6) port G2 in the slidevalve will register with release vent port lll in the so that the slidevalve chamber 25 will he vented to atmosphere by Way port 62, port 4K4-,Tl, valve chamber 23?), se t and pressage 236, and such venting willcontinue long as the valve 239 remains open. The etl'ec' to acceleratethe release movement or i piston Q7. Moreover, when valve 289 closes andvalve 237 opens, ivill occur when the engineers brake valve is movedaway 'Src-m holding position, the air to opera e tee piston 228 and openthe i'alve 223 .is drawn 'trom the slide valve chamber by way el assa-Oell and this action further assiss n n t. the releasing movement ot thepi., 24

This venting of the slide valve chamber is important in any case becauseit insures b the simultaneous action olf all release magnets 2st-2tliroughout the train, the prompt simultaneous movement of the triplevalves to release position.

It 1s even more important where t n emergency position thn use ot thesupp ein reservoir, or the use oit the main reservoir pressure, or both,produces a liralre cylinder pressure substantially as hi gli or evenhigher than brake pipe pressure. Under the condit-ions just recitedreleasing` movement of the triple valve would he sluggish and in somecases would not occur at all ezrcep the provision of this seecial vent.

In eases Where the omission of the main reservoir connection or the mainreservoir connection and the auxiliary reservoir connection, precludesthe existence or loi-alize cylinder pressures abnormally high relativelyto brake pipe pre sure, the ports lll and 62 may e omitted with theconsequent omission oiE the directI venting action. 'l such cases,however, the Withdrawal et air from the slide valve chamber Q to actual;piston 228, performs a useliul ser yice in assisting the releasingmovement of the triple valve as already explained.

Train connections.

The diagram of Fig. l shows the equipment for tivo cars. Each car haspipe bracket A, triple valve ll, emergency valve C, pneumatic sivitch B,emergency lay-pass valve E, electro-pneumatic valve F, constructed asalready described. rlhe auxiliary reservoir is shown at Gr, supplementalreservoir at H, brake cylinder at K, the

hralre pipe at L, and the main reservoir pipe at lli. rllhe wipes lliand M are coupled trom ear 'to car ly automatic couplings N, ll. Thelelitivard ot the Ivo .cars is assumed to eg running, in which, mainreservoir aM lcd lo the lu'alre pipo through a reducing valve; lmlding,ivnich in its pneumatic elnracteristies is the same as running, but isdiliierent as to electrical characteristles; l lap 7, in which all.brake valve ports are blanlred; service in which is vented 'from theequaliaing discharge voir to produce a graduated venting of liralie pipethrough the actuation oit the equalia Y il, vv rich the hralze pipe isvented directly i sphere lifes oli' this character are u'cll known lreduire no detailed description. Such valvee-: are connected to the1oninch pipes ym., on the motor ear and .l2 'm2 ou the trailer. 'theremay lie more than one valve on each tlirougnout the length of the edbetween hy couplers indirally hy die letter ln the l serves as a commonis connected to' one, terminal of e windings lik, ild, and .Q1-ll. rlheis conn eted to one terminal, say terminal ot each of the batheine' ozeliattery on each t ci' each 1cattery rough a corre Houding sivitch ehere is one on each car, ivith ia'hich also eztends throughout rthere isalso a servire circuit re 255, a re Saso circuit Wire Q56, an emergencyeireuit Wire 25?', each olf which extends tnroughout the train. 'lheservice circuit Wire 255 is connected to the remaining terminal of eachel the coils 2j); the Wire 256 connected to the remaining terminal ofeac-lr olf the coils 2452, and the ivire 257 is cour ed to the remainingterminal of each the coils 15,92.

' common practice in the electroart, the engineer-s hralre valvecontrols the admission and exhaust dis/,marge piston, and einer-V CII257. The Wire` 254 is connected with an arcuate contact 258 with whichthe contactor 259 is always in contact. The handle ot' the engineersbrake valve diagrammatically illus rated at and the characteristicpositions of this handle in release running. holding, lap service andemergency positions, are designated by legends.

The service Wire 255 connected to a contact 262 which is engaged by thecontacter 259 only when the handle 261 is in service position. to therelease Wire 256 and engaged by contactor 259 only when the brake handle261 is in holding position. There is a Contact 261 which is sopositioned as to be engaged bythe contactor 259 only when the valvehandle 261 is in emergency position. Con-- tact is connected toemergency Wire 257.

The showing of the sketch only dia` grammatic but will indicate that inrelease, running! and lap positions no circuits are established, and thewindings 192, 242 and 210 are deenergized. ln holding position theWinding 242 alone is energized by a circuit established through Wire256. In service position the winding 216 is energized by circuitestablished through the Wire 265 and in emergency Windingr 192 isenergized h v a circuit` established througlithe Wire T. It. will beobserved, therefore, that the [litter-ence between holding position andruiming' position is merely Whether or not the Winding` 242 isenergized. lVhen energized. the exhaust port from each triple valve Willbe closed. At the same time the slide valve chamber 25 will be vented toatniosphere and such vent-ingr will continue until the slide valve ismoved to release position.

The tivo contacts 152, 152 ofthe pneumatically operated switch D areconnected byV Wires and 266 with the wire and the emergency Wire 257respectively. When the piston 14,1 is forced down on any car contact1413 bridges the contacts 152 and estab lishes a connection betweenWires 254 and 257 independently of the action of the `en- ;i'ineersbrake valve and switch and accordingly the windings 192 throughout thetrain yare excited to produce an immediate emer- `fzency applicationthrough the venting of the train Y 'pe and the consequent movement ofthe tripe valve to emergency position.

Description of operation.

On a rise of brake pipe pressure initiated There is a Contact 263connected at the engineers brake valve. piston 27 will move to the rightuntil arrested by the retard stop 3T, and charging will take placethrough the ports 13 and 53. Brake pi air will tlow through passage R64tothe chambers 175 and 195 and inasmuch as the emergency and servicewindings 192 and 21o' are inert. the valve chambers 184 and 206 will besimilarly charged. Thus the valves 170 and 190 will be closed. In theemergency valve mechanism piston 105 Will be moved to its lowermostposition and charging; of the reservoirs 102 and 115 will take place, aspreviously described. If the risc in brake pipe pressure should be moresudden, piston 27 would overpower spring 38, rendering the quickcharging port 54 etree# tive and suspending the charging of thesuppleuiental reservoir through ports 52 and Should this quick chargingresultin overchargingot the auxiliary reservoir, equalization betweenthe auxiliary reservoir and the supplemental reservoir, which oc` cursimmediately piston 27 `moves back'to normal charnino position, willlargely dissi- CD D pate the overcharge.

Semic@ application..

Upon a service reduction of pressure initiated by the eutrinees` brakevalve there will be areduetion of brake pipe pressure through the actionof the equalizing dis charge valve. On each car also the winding 216will be energized While the engineers brake `valve is in serviceposition, and this will result in opening of the valve 196 and each`triple valve to the brake cylinder through Vthe choke 202. Either or`both means ot reducing `brake pipe pressure mightinitiate serviceapplication, but" the tivo together produce a simultaneous reduc` tionin all triple valves so `that the `piston 2T starts toward serviceposition promptly. As it moves toward service, cavity 57 con'` nectsports 53 and 5Fl,y thus venting thebralre pipe passage 6l into the quickservice cham-` ber 39. This local venting further accelerates themovement of the piston 27' t0 service position. In such position port 60by its registry with ort 47 admits auxiliary reservoir air to the )rakecylinder. At the saine time port 63 by connecting ports 48 `and 49 makesthe safety valve 41 ctective` to limit the brake cylinder pressure `inservice. Y l

During the operations above described, the emergencywinding 192 and therelease winding 242 remain deenerp'ized. At this time nothing occursinthe emergency valve except that piston 105 rises until arrested bytheengagement of pins 113 Wlth `flange 89. Reservoir 102 is vented at arate com-` mensurate with a. service reduction of pres-` sure.

`the venting` of `the brake pipe passage, on`

lao

Emergency application.

It the engineer moves his brake valve to emergency position he vents thebralre pipe to atmosphere and produces a sudden pronounced reduction ofbalze pipe pressure. At the same time the emergency magnet valvefunctions to close supply valve 188 and open exhaust valve 187, thuscausing the valve 176 on each triple valve to open and vent the brakepipe directly to atmos phere. The sudden local pressure drop also causespiston to move upward to its extreme emergency position, opening thevalve 35 and Jrurther venting` the brake pipe through passage 83 andvalve 92. he brake pipe is thus rapidly vented by three independentagencies. The piston 23 moves rapidly lettward to its limit oit motion,seats against the cap gash t, and so positions the slide valve that boththe auxiliary reservoir and vthe supplemental reservoir equalize withthe brake cylinder. At the same time the back pressure retained by thevalve 92 tloivs through the passage 11iand forces the piston 1111 doivnto bridge the Contact 152. Since the emergency Winding 192 is assumedalready to be energized, the action ot the pneumatic switch D producesno additional result, but it is an additional safety feature providingtor possible tailure ot' a train circuit, by energizing` the emergencyWinding on a particular car directly through the circuit and battery onthat oar.

The pressure in passage 114 also is communicated to the space belowpiston 158 and forces this upward to unseat valve 165 admit mainreservoir air directly to the bralre cylinder passage 7 2 by Way etcheclr valve 171. Since main reservoir pressure is much higher than thatcarried in the auxiliary or supplemental reservoir, or the brake pipo,the opening` et valve establishes an abnormally high brale cylinderpressure.

Excess pressure vented by the safety' valve 173, the safety valve 411`which responds at Va loiver .`pressure, being discrmnecterJ through theaction oitV the triploV slide valve 35 (see Fig.

In 'the event that a portion of the train pipe were cut olf through atrozen hose or an accidentally closed angle cock, the gradual depletionot pressure in that isolated portion the brake pipe,A would, as aboveexplained,- ultimately lead to the downward shitting ot the piston valve126, followed by the motion ot the piston 105 to emergency position. ltassumed that When this occurs the engiueers bralre valve is in releaseor running position. Pressure retained by the valve Q2 acting; throughthe passage 1111` actuates the rpneuinatically operated svvitchl) andthrough the connections described, energizes the emergency windings 192on all the cars throughout the train. This produces au immediatctlyomergency application through the response oit all the triple valves ontho train to the resulting local venting` ot the brake pipe toatmosphere at each valve. Response oli all the emergency valves C wouldbi about an admission ot' main reservoir air in the manner alreadydescribed.

ieleose after serio-ice.

In release after servico the pressure .in the valve chainber 25 lessthan normal brake pipe pressure, and in some cases satistactory resultscan be secured by moving; the engineers brake valve to runuinl position.But the better practice is to move the valve to holding position toacceler te the resultingmovement of the pistons After an emergencyapplication, in `which main reservoir air has been admitted to the brakecylinder, brake cylinder pressure maj, be high or higher than the nomalbrake pipe pressure. Y To release, under these conditions, the engineershrahc valve must be moved to holding position, in i-.vhich 1position theslide valve chamber vented to atmosphere, as already described. lllhenthis has caused the triple valve piston to move to release position.venting will be stopped, because port 52' u'ill have out ot registrywith port lhe thenV moves his brake valve handle to running,` position.Bridging `or the contacts 152 and the opening of the valii'es 165 areonly temporary, in any even ttor the reason that the port 159 soon ventsthe pressure retained in the passage l1-il by the valve lt should beclearly understood that .iu the diagrammatic Figure l, there have beenincluded only those parts ncccssarv to su understanding ot the presentir Various details, in addition to the ei neer`s brake valve, have beenomitted, because they merely conform to standard practice and theirpresence Would confuse the diagram.

lt is not always necessary to use a valve Which gives an emeipenrypressru'e as high as or higher than pipe pressure, and in such czse themain r Voir connection 17 and the lay-pass valve mechanism li can beomitted. The same is true ot tho supplemcntal reservoir. rllhe omissionot the Til llt)

`ifmausa supplemental reservoir, and particularly the omission of themain reservoir connections, reduce in a. large measure the necessity forthe ports (32 and la, und in. some cases these rcleasevent ports may beomitted. In such case there material advantage in deriving the pressurefluid to actuate the piston Q28 directly from the slide valve chamber`i'or this accelerates the releasingr ol' the piston Heretofore indevices of this general char-- actcr it has been the practice to derivethe air for operating the release valve piston 228 from the brake pipe,just as is done in the present structure in the case ot an emergencyvalve lio and the service lvalve 196. 'The Withdrawal oi" air from thebrake pipe during1 release, has the effect ot' retarding the releasingmotion of the pistoin'so that as contrasted 'with the old relation, theone here described presents a marked improvement. The use oit a slowreduction emergency valve, broadly considered, is claimed in my priorapplication above identified, but derives peculiar advantage iinconjunction with the pncumatically operated switch D, because when socombined the slow emergency application is produced simultane ously onall the cars of the train.

Various changes in the speciiic structure of the component elements areobviously possible and are contemplated.

lVhat is claimed is,m y

i. The combination of a brake pi e; an auxiliary reservoir; a triplevalve raving a slide valve in a chamber connected with the auxiliaryreservoir, and a piston interposed between said chamber and the brakepipe; means for venting said chamber; electiically controlled means foractuating said vi ting` means, and means for reiulering said venting'means inelicctive when said triple *alve is in release position.

2. The coii'ibination ot' a brake pipe; an auxiliary reservoir; a triplevalve having a slide valve in a chamber connected with the auxiliaryreservoir, and a piston interposid between `said chamber-and the brakepipe; means for retardinir i'low` from said auiliary reservoir to saidchamber; means for von u. 5 said chamber; and electrically imitiolledmeans for actuating said venting,l means.

5. The combination ot' a brake pipe; an auxiliary reservoir; a triple`valve having a slide valve in a chamber connected with the auxiliaryreservoii-aiid a piston inter posed between said chamber and the brakepipe; a vent conduit leading from said chamber and controlled by saidslide alve so as to be open in lap and application p0- sitions.: and anelectrically controlled valve also controlliner said vent conduit.

et. The combination of abrake pipe; an auxiliary reservoir; a triplevalve having a slide valve in a chamber connected with the auxiliaryreservoir, anda piston interposed between said chamber and the brakepipe: means loi retardiniir flow from said auxiliary reservoir to saidchamber; a vent 'ond uit leadingr from said chamber and controlled bysaid slide valve so as to beopen .in lap and application positions;andan electrically controlled valve also controlling said vent conduit.l

5. lhc combination of a brake pipe; `an auxiliary reservoir; a triplevalve having,r a slide valve in a chamber connected with the auxiliaryreservoir; `and a piston interposed between said chamber and the brakepipe; a vent `conduit leading from said chamber and controlled by saidslide valve so as to be open in application and lap `positions: a secondvalve also cont-rolling said vent conduit; and means independent of thebrake pipe for actuatingr said second valve.

The combination of abrake pipe; `an auxiliary reservoir; a triple valvehavinp` a slide valve in a chamber connected with the auxiliaryreservoir` and-a piston inter poseil between said chamber and the brakepipe: means for retarding flow from said auxiliary reservoir to saidchamber; a vent conduit leading from said chamber and con trolled bysaid slide valve so as to beopen in application andlap positions; asecond valve also controlling said ventconduit; and means independent ofthe brake pipe for actuating said second valve. y

`T. The combination of a main reservoir charged at a relatively highpressure; a brake pipe ted therefrom and maintained under a lovverpressure; an auxiliary reseri oo voir; a brake cylinder; atriple valvehavingr a slide valve in a chamber connected with the auxiliaryreservoir and a piston interposed between said chamber and the `brakepipe. the triple valvecontrolling the i charging' ofthe auxiliaryreservoir" from the brake pipe, the admissionof auxiliary reser-` voirair through said chamber to'thehrake cylinder in service andeinergencypandthe exhaust of pressure from 4the brake cylinderA inrelease, said slide valve controllingia vent port open only `in lap andapplication positions and leading `from said chamber; an emergency valvemechanism associated with said triple valve and serving;r in emergencyailiplications to admit main reservoir air `to the brake cylinder; andan electrically controlled valve independently controlling said ventport.V y y.

8. The combination of a main reservoir charged at a relatively highpressure; a.

brake `pipe. `fed therefrom and maintained I under a lowerpressm'e; anauxiliary` reserf voir a brake cyliiuler; a `triple valve having a slidevalve in a chamber oonnectett with. the auxiliary reservoir and a pistonin`- terposed between said chamber and the valve mechanism adapted toadmit air from one or both said reservoirs accordlnff to the nature ofthe brake applicationA7 and toV exand said relief valve in such manneras to be open when said relief valve is open and the triple valve is ina brake applying position.

lil. In an electro-pneumatic brake system, the combination of a brakeipe; an auxiliary reservoir; a triple va ve mechanism adapted to admitair from said reservoir, and to exhaust the brake cylinder, said valveincluding a triple piston subject in one direction to brake pipepressure; a retainer valve controlling tbe exhaustpassing through thetriple valve; means urging said valve closed; a pressure motor arrangedto ovcrpower said means when pressure is admitted thereto; admission andrelief valve .mechanism operable alternately to admit air from theauxiliary reservoir side of the triple piston to said pressure motor andto vent said motor; and a vent connection from the auxiliary reservoirside of the triple piston to atmosphere controlled conjointly by saidtriple valve and said relief valve in such manner as tobe open when saidrelier' valve is open and the triple valve is in a brake applyingposition.

l?. In an electro-pneumatic brake system, the combination of abrakepipe; an auxil iary reservoir; a supplemental reservoir; a brakecylinder; a triple valve controlling the charging of both reservoirs,the release oi' pressure from the brake cylinder, the admission ofauxiliary' reservoir air to the brake cylinder in service applicationsand the admission ot air from both reservoirs to the brake cylinder inemergency applications; electrically actuated emergency valve connectedto cause the emergency function of the triple valve; a pneumaticallyactuated emergency valve controlled by brake pipe pressure and connectedto cause the emergency function oi' the triple valve; and means renderedeifective by abnormal depletion of brake pipe pressure to render anemergency valve active.

i8. ln4 an electro-pneumatic brake system, the combination of a brakepipe; an auxiliary reservoir; a supplemental reserhaust the brakecylinder, said valve including voir; a brake cylinder; a triple valvecontrolling the chargin of both reservoirs, the release of pressure romthe brake cylinder, the admission of auxiliary reservoir air to the.brake `cylinder in service applications and the admission ot air fromboth reservoirs to the brake cylinder in emergency applications; anelectrically actuated emergency valve connected to cause the emergencyfunction of the triple valve; a pneumatically actuated emergency valvecontrolled by brake pipe pressure and connect-` ed to cause theemergency function of the triple valve; and means rendered eilective byabnormal depletion of brake pipe pressure to render both of saidemergency valves active.

19. In an electro-pneumatic brake system, the combination of a brakepipe; an auxiliary reservoir; a supplemental reservoir; a brakecylinder; a triple valve controlling the charging of both reservoirs.the release of pressure llrom the brake cylinder, the admission ofauxiliary reservoir air to the brake cylinder in service ap licationsand the admission of air from bot reservoirs to the brake cvlinder in.emergency applica-` tions; an electrically actuated emergency valveconnected to cause the emergency function of the triple valve; apneumatically actuated emergency valve controlled `by brake pipepressure and connected to cause the emergency function of the triplevalve; means rendered effective by abnormal depletion of brake pipepressure to render an emergency valve active, and electric and pneumaticconnections between said two emergency valves, whereby the functioningof either causes the other to function.`

20. In an electro-pneumatic brake system, the combination of a brakepipe; an auxiliary reservoir; a supplemental reservoir;

a brakecylinder; a triple valve controlling the charging of bothreservoirs, the release of pressure from the brakecylinder, theadmission of auxiliary reservoir airitolthe brake cylinder in service aplications and the admission of air from oth reservoirs nsl to the brakecylinder in emergency applications; an electrically actuated emergencyvalve connected to cause the emergency function of the triple valve; apneumatically actuated emergency valve controlled by brake pipe pressureand connected to cause the emergency function of the triple valve; meansrendered effective by abnormal depletion of brake pipe pressure torender both of said emergency valves active; and electric and pneumaticconnections between said two emergency valves; whereby the functioningof either causes the other to function` y t 21. In an electro-pneumaticbrak system for use on vehicles to be connected in trains, thecombination of a brake pipe; an

auxiliary reservoir; a supplemental reservoir; a brake cylinder; a tiplc valve controlling` the charging of both reservoirs, the release ofpressure from the brake cylinder, the admission of auxiliary reservoirair to the brake cylinder in service applications and the admission ofair from both reservoirs to the brake cylinder in emergencyapplications; an electrically actuated emergency valve connected tocause the einergency function of the triple valve; a pneu maticallyactuated emergency valve controlled by bral/,te pipe pressure andconnected to cause the emergency functionV of the triple valve; meansremlerad effective by abnormal depletion of brake pipe pressure torender an emergency valve acive; and electrical connections forestablisbirri;` circuit including the electrically actuated emergencyvalves of various vehicles connected in a train, whereby if an emergencyvalve of one vehicle functions all function.

22. In an electro-pneumatic brake system for use on vehicles to beconnected in trains, the combination of a brake pipe; an aus; iliaryreservoir; a supplemental reservoir; a brake cylinder; a triple valvecontrolli .f the charging of both reservoirs; the reir i of pressurefrom the bralqe cylinder, Vthe l mission of auxiliary reservoir air tothe brake cylinder in service applications and the admission of air fromboth reservoirs to the brake cylinder in emerigency applications; anelectrically actuated emr valve connected to cause the emergencyfunction of the triple valve; a pneuinatical ly actuated emergency valvecontrolled by brake pipe pressure and connected to cause the emergencyfunction of the triple valve; means rendered effective by abnormaldepletion of brake pipe pressure to render both of said emergency valveactive; and electrical connections for establishinel a circuitincluding,` the electrically actuated emergency valves of variousvehicles connected in a train, whereby if an emergency valve of vehiclefunctions all function.

Q3. In an electro-pneumatic brake system; for use on vehicles to beconnected in trains7 the combination of a brake pipe; an auailiaryreservoir; a supplemental reservoir; a brake cylinder; a triple valvecon the chargine of both reservoirs; the rele MC2 of pressure from thebrake rider, "Lie admission of auxiliary reservoir air to t bralrecylinder in service applications and the admission of air from bothreservoirs to the brake cylinder in emergency appli ations; anelectrically actuated emergency valve connected to cause the emergencyfunction of the triple valve; a pneumatically actuated emergency valvecontrolled by brake pipeV pressure and connected to cause the emergencyfunction of the triple valve; means rendered effective by abnormaldeinname pletion of bralre pipe pressure to render an emergency valveactive; electric and pneumatic connections between said two emergencyvalves whereby the functioning of either causes the other to function;and electrical connect-ions for establishing` a circuit including theelectrically actuated emergency valves of various vehicles connected ina train, whereby if an emergency valve of one vehicle functions allfunction.

2a. in an electrapneumatic brake system, for use on vehicles to beconnected in trains; the combination of a brake pipe; an au iliaryreservoir; a supplemental reservoir; a brake cylinder; a triple valvecontrolling` the charginp` of both reservoirs, the release of pressurefrom the brake cylinder', the admission of auxiliary reservoir air tothe brake cylinder in service applications and the admission of air fromboth reservoirs to the brake cylinder in emergency applications; anelectrically actuated en'iergency valve connected to cause the emergencyfunction of the triple `valre; a pneumatically actuated emergency Valvecontrolled by brake pipe pressure and connected to cause the emergencyfunction of the triple valve; means rendered effective by abnormaldepletion of brake pipe pressure to render both of said emergency valvesactive; electric and pneumatic connections between said two emergencyvalves; whereby the functicninpl of either causes the other to function;and electrical connections for establishing` a circuit including;T theelectrically actuated emergency valves of various vehicles connected ina. train7 whereby if an emergency valve of one vehicle functions allfunction.

ln an electro-pneumatic brake system for use with vehicles to beconnected in trains, the combination of a main reservoir chargedrelatively high pressure; a bralre pipe fed therefrom at a lower presure: an auxiliary reservoir; a brake cylinder; a triple valvecontrolling the charging' said reservoir from the brake pipe, therelease of pressure from the brake cylinder; and the adn -ssion ofauxiliary reservoir pressure to the brake cylinder; emergency -valvemechanism operalile pneuniatically by brake pipe pressure and ser 'ingto admit main reservoir air to the brake cylinder; electical means forcausiiig` said emergency valve mechanism. to function by locallydepletinggI brake pipe pressure; and pneumatic means associated withsaid emergency valve rendered effective by abnormal. depletion of brakepipe pressure to cause said emergency valve to function.

in an electropneuinatic brake system for use with vehicles to beconnected in trains, the combination of a main reservoir charged atrelatively high pressure; a brake pipe fed therefrom at a lowerpressure; an

auxiliary reservoir; a brake cylinder; a triple Valve controlling thecharging of said reservoir from the brale pipe, the release of ,pressurefrom the brake cylinder and the admission of auxiliary reservoirpressure to the brake cylinder; emergency valve mechanism operablepneumatically by brake pipe pressure and serving to admit main reservoirair to the brake cylinder;

electrical means for causing said emergency valve mechanism to functionby locally depleting brake pipe pressure; pneumatic means associatedwith said emergency Valve and rendered effective by abnormal depletionof brake pipe pressure to cause said emergency valve to function: anelectric switch adapted to be actuated by the functioning of saidemergency valve; and connections for establishing a circuit controlledby said switch, includingr said electrical means and capable ofconnection with similar circuits ou other similarly equipped Vehicleswhen connected in train; to ensure simultaneous operation of allemergency valves if one of said emergency valves should function.

27. In an electro-pneumatic brake system; the combination of a pluralityof automatic air brake car equipments connected in a train by a brakepipe; electrical application producing means associated with each carequipment; an automatic mechanism in cluding an electric switchassociated with each car equipment and adapted to respond to abnormaldepletion of brake pipe pressure; and electric connections arranged toplace each of said switches in controlling relation to the electricalapplication producing means of equipments connected by said brake pipe.

28. In an electro-pneumatic brake system; the combination of a pluralityof automatic air brake car equipments connected in a train by a brakepipe, and each including a triple valve and an emergency valvecontrolled by brake pipe pressure; electrical brake pipe Venting meansassociated with each car equipment; means associated with each emergencyValve and responsive to abnormal depletion of brake pipe pressure tocause said valve to function; a switch operated. by the functioning ofthe emergency valve; and electric connections arranged to place eachsuch switch in controlling relation with the electrical brake pipeventing means of the car equipments connected by 'said brake pipe.

29. In an electro-pneumatic brake system, the combination of a triplevalve; an electrically actuated emergency valve connected to cause theemergency :function of the triple valve; a pneumatically actuatedemergency valve connected to cause independeutly an emergency functionof the triple valve; connections between said emergency valves whereby`the functioning of either causes the other to function; and connectionsbetween a plurality ofwsaid electrically actuated emergency valves in atrain whereby if ene functions all function.

30. In an electro-pneumatic brake system; the combination ofa triplevalve; an electrially actuated emergency valve connected to cause theemergency function of the triple valve; a pneumatically actuatedemergency Valve connected to cause indepenthintly an emergency functionof the triple `valve; and connections between said emergency valveswhereby the functioning of either causes the other to function;

31. The combination of a brake pi nel; an auxiliary reservoir; a brakecylin er; a triple `Valve; an emergency valve operable by brake pipepressure independently of the triple valve and functioning to dischargeair from the brake pipe; an electrically actuated vent valve operable tovent air from the brake pipe; and a pneumatically actuated switchconnected to be closed as an incident to the discharge of air throughthe first named emergency valve and serving when closed to establish anenergizing circuit through said electrically actuated vent valve.

Si A brake equipment for vehicles intended to be coupled in trains;comprising in combination a brake pipe; an auxiliary reservoir; a brakecylinder; a triple Valve; an emergi-uicy valve operable by brake pipepressure independently of the triple valve and functioning to dischargeair from the brake pipo; an electrically actuated vent valve operable tovent air from the brake pipe; a pneumatically actuated switch arrangedto be closed by the discharge of air through the first named emergencyvalve; and electrical connections adapted to establish an energizingcircuit through said electrically actuated vent valve and other similarValves of connected vehicles.

33. The conibination of a main reservoir charged at relatively highpressure; a brake pipe fed therefrom at a lower pressure; an auxiliaryreservoir; a brake cylinder; a triple Valve associated With saidreservoir brake pipe and brake cylinder; an emergency Valve operable bybrake pipe pressure independently of the triple valve and functioning todischarge air from the brake pipe; and a pneumatically actuated valvearranged to be opened by the discharge of air through said emergencyvalve and serving when opened to admit air from the main reservoir tothe brake cylinder. y

Si. The combination of a main reservoir charged at relatively highpressure; a brake pipe fed therefrom at a lower pressure; an auxiliaryreservoir; a brake cylinder; a triple valve associated with saidreservoir bake pipe and brake cylinder; an emergency valve operable bybrake pipe pressure independently of the triple valve and functioning todischarge air from the brake pipe; afpneumatically actuated Valvearranged to be opened as an incident to the discharge of air throughsaid emergency Valve and serving when opened to admit nir from the mainreservoir to the brake cylinder; an electrically actuated vent Valve operable to vent air from the brake pipe; and a pneumatically actuatedswitch arranged to be closed by the discharge of air through Saidemergency valve, and serving when closed to establish an energizingcircuit thilreugh said electrically actuated Vent va ve.

auxiliary reservoir; and a check valve preventing flow ci? .euchemergency reservoir air te the supplemental reservoir.

ln testimony u'hereol'f have Signed my name to this Specification.

CHARLES A. CAMPBELL.

